12856009 has 2 divisors, whose sum is σ = 12856010. Its totient is φ = 12856008.

The previous prime is 12856007. The next prime is 12856013. The reversal of 12856009 is 90065821.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 11799225 + 1056784 = 3435^2 + 1028^2 .

It is a cyclic number.

It is not a de Polignac number, because 12856009 - 2¹ = 12856007 is a prime.

Together with 12856007, it forms a pair of twin primes.

It is not a weakly prime, because it can be changed into another prime (12856007) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 6428004 + 6428005.

It is an arithmetic number, because the mean of its divisors is an integer number (6428005).

Almost surely, 2^12856009 is an apocalyptic number.

It is an amenable number.

12856009 is a deficient number, since it is larger than the sum of its proper divisors (1).

12856009 is an equidigital number, since it uses as much as digits as its factorization.

12856009 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 4320, while the sum is 31.

The square root of 12856009 is about 3585.5277156926. The cubic root of 12856009 is about 234.2621128423.

The spelling of 12856009 in words is "twelve million, eight hundred fifty-six thousand, nine".